In severe climates where subfreezing temperatures occur over prolonged periods of time, water pipes and water troughs must be protected from freezing in order to allow access by livestock to a readily available and replenishable water supply. There have been many prior art devices which have dealt with maintaining the supply pipes and/or the drinking receptacle ice free. The inventor of the instant device was himself granted U.S. Pat. Nos. 4,091,261 and 4,069,409 which were directed towards maintaining the water supply pipes to a livestock watering assembly ice free.
Some of the problems associated with the prior art devices have been: an inability to regulate the flow to the trough or receptacle in response to the demand of the livestock; the use of complex heating elements which transferred too much heat to either the supply pipe or receptacle resulting in warm water which the animals are reluctant to drink, or a hot receptacle surface which would burn the animals muzzle and discourage them from utilizing the trough; improper insulation on the heating element, resulting in electrical current being passed through the receptacle and shocking the livestock upon contact, thereby causing them to completely avoid the watering trough; and improper placement of the heating element with respect to the supply pipe or receptacle, resulting in too little heat being transferred to the components with subsequent ice formation, frustrating the livestock's attempts to obtain water. Other problems that have plagued the designers of heated livestock watering assemblies have been; the freezing of the valve heat to the valve seat in the outlet section; unregulated pressurized water striking the livestock upon depression of the actuator lever; formation of ice on the surface of the trough or receptacle in exceptionally cold weather, imprisoning the actuator arm in the ice; and the disposition or construction of the actuator per se, such that even after the actuator has been depressed and water supplied to the trough, the actuator pesents an obstacle to the livestock attempting to gain access to the water. A further problem has been the accumulation of sediment, including feed from the animals' mouths, in livestock drinking receptacles.
The present invention was designed to eliminate these problems as will hereinafter be described.